The invention comprises the synthesis of linear and which will hereinafter be termed "three arm star" polyisobutylenes carrying two and three terminal styryl end groups respectively, and their copolymerization to form novel branched and network polymers. Monomers used in the copolymerization include vinyl acetate and N-vinyl-2-pyrrolidone.
A number of patents in the prior art deal generally with the copolymerization of polyisobutylene. U.S. Pat. No. 4,327,201 discloses the formation of graft copolymers using macromolecular monomers having a polyisobutylene backbone. There is however no disclosure of a styryl-telechelic polyisobutylene having a terminal functionality of either two or three. Further, neither branched nor network copolymers are produced. U.S. Pat. No. 4,342,846 relates to blends of polyester resin and an impact resistant interpolymer comprising crosslinked acrylic or methacrylic rubber, crosslinked styrene-acrylonitrile, and uncrosslinked styrene-acrylonitrile polymer components. There is no disclosure of branched or network copolymers as disclosed by applicant.
U.S. Pat. No. 4,316,973 refers to terminally functional olefin and hydroxy polymers having polyisobutylene as the backbone. There is no teaching of the formation of styryl end groups or copolymerizations with either vinyl acetate or N-vinyl-2-pyrrolidone. U.S. Pat. No. 4,276,394 describes the synthesis of diterminally halogenated polyisobutylenes and their subsequent reaction to form thermoplastic elastomer block copolymers. There is no disclosure of the compounds named in this application. U.S. Pat. No. 4,262,095 describes 3-block copolymers comprising mixtures of plastomeric and elastomeric segments. One disclosed block copolymer is styrene-isobutylene-styrene. There is no disclosure however of a polyisobutylene having single styryl head and tail groups.
U.S. Pat. No. 4,036,788 refers to the use of N-vinyl-2-pyrrolidone and other N-vinyl-lactams in combination with other components to produce anionic hydrogels. The invention contains no recitation of the use of polyisobutylene and thus is not pertinent. U.S. Pat. No. 4,011,178 describes the polymerization of selected methyl branched .alpha.-olefins and aromatic monomers such as styrene and .alpha.-methylstyrene. Block copolymers are disclosed such as styrene-isoprene-styrene and styrene-butadiene-styrene. There is no teaching however of styryl end capped polyisobutylene or of the copolymers taught by applicant.
U.S. Pat. No. 3,786,116 is a rather comprehensive patent dealing in general with the various types of graft copolymers which can be produced utilizing polyisobutylene. There is no disclosure of the use of styryl end groups to produce subsequent copolymerizations having branched or network characteristics.